eslint-plugin-react/lib/rules/jsx-tag-spacing.js

/**
 * @fileoverview Validates whitespace in and around the JSX opening and closing brackets
 * @author Diogo Franco (Kovensky)
 */
'use strict';

const getTokenBeforeClosingBracket = require('../util/getTokenBeforeClosingBracket');
const docsUrl = require('../util/docsUrl');

// ------------------------------------------------------------------------------
// Validators
// ------------------------------------------------------------------------------

function validateClosingSlash(context, node, option) {
  const sourceCode = context.getSourceCode();

  const SELF_CLOSING_NEVER_MESSAGE = 'Whitespace is forbidden between `/` and `>`; write `/>`';
  const SELF_CLOSING_ALWAYS_MESSAGE = 'Whitespace is required between `/` and `>`; write `/ >`';
  const NEVER_MESSAGE = 'Whitespace is forbidden between `<` and `/`; write `</`';
  const ALWAYS_MESSAGE = 'Whitespace is required between `<` and `/`; write `< /`';

  let adjacent;

  if (node.selfClosing) {
    const lastTokens = sourceCode.getLastTokens(node, 2);

    adjacent = !sourceCode.isSpaceBetweenTokens(lastTokens[0], lastTokens[1]);

    if (option === 'never') {
      if (!adjacent) {
        context.report({
          node: node,
          loc: {
            start: lastTokens[0].loc.start,
            end: lastTokens[1].loc.end
          },
          message: SELF_CLOSING_NEVER_MESSAGE,
          fix: function(fixer) {
            return fixer.removeRange([lastTokens[0].range[1], lastTokens[1].range[0]]);
          }
        });
      }
    } else if (option === 'always' && adjacent) {
      context.report({
        node: node,
        loc: {
          start: lastTokens[0].loc.start,
          end: lastTokens[1].loc.end
        },
        message: SELF_CLOSING_ALWAYS_MESSAGE,
        fix: function(fixer) {
          return fixer.insertTextBefore(lastTokens[1], ' ');
        }
      });
    }
  } else {
    const firstTokens = sourceCode.getFirstTokens(node, 2);

    adjacent = !sourceCode.isSpaceBetweenTokens(firstTokens[0], firstTokens[1]);

    if (option === 'never') {
      if (!adjacent) {
        context.report({
          node: node,
          loc: {
            start: firstTokens[0].loc.start,
            end: firstTokens[1].loc.end
          },
          message: NEVER_MESSAGE,
          fix: function(fixer) {
            return fixer.removeRange([firstTokens[0].range[1], firstTokens[1].range[0]]);
          }
        });
      }
    } else if (option === 'always' && adjacent) {
      context.report({
        node: node,
        loc: {
          start: firstTokens[0].loc.start,
          end: firstTokens[1].loc.end
        },
        message: ALWAYS_MESSAGE,
        fix: function(fixer) {
          return fixer.insertTextBefore(firstTokens[1], ' ');
        }
      });
    }
  }
}

function validateBeforeSelfClosing(context, node, option) {
  const sourceCode = context.getSourceCode();

  const NEVER_MESSAGE = 'A space is forbidden before closing bracket';
  const ALWAYS_MESSAGE = 'A space is required before closing bracket';

  const leftToken = getTokenBeforeClosingBracket(node);
  const closingSlash = sourceCode.getTokenAfter(leftToken);

  if (leftToken.loc.end.line !== closingSlash.loc.start.line) {
    return;
  }

  if (option === 'always' && !sourceCode.isSpaceBetweenTokens(leftToken, closingSlash)) {
    context.report({
      node: node,
      loc: closingSlash.loc.start,
      message: ALWAYS_MESSAGE,
      fix: function(fixer) {
        return fixer.insertTextBefore(closingSlash, ' ');
      }
    });
  } else if (option === 'never' && sourceCode.isSpaceBetweenTokens(leftToken, closingSlash)) {
    context.report({
      node: node,
      loc: closingSlash.loc.start,
      message: NEVER_MESSAGE,
      fix: function(fixer) {
        const previousToken = sourceCode.getTokenBefore(closingSlash);
        return fixer.removeRange([previousToken.range[1], closingSlash.range[0]]);
      }
    });
  }
}

function validateAfterOpening(context, node, option) {
  const sourceCode = context.getSourceCode();

  const NEVER_MESSAGE = 'A space is forbidden after opening bracket';
  const ALWAYS_MESSAGE = 'A space is required after opening bracket';

  const openingToken = sourceCode.getTokenBefore(node.name);

  if (option === 'allow-multiline') {
    if (openingToken.loc.start.line !== node.name.loc.start.line) {
      return;
    }
  }

  const adjacent = !sourceCode.isSpaceBetweenTokens(openingToken, node.name);

  if (option === 'never' || option === 'allow-multiline') {
    if (!adjacent) {
      context.report({
        node: node,
        loc: {
          start: openingToken.loc.start,
          end: node.name.loc.start
        },
        message: NEVER_MESSAGE,
        fix: function(fixer) {
          return fixer.removeRange([openingToken.range[1], node.name.range[0]]);
        }
      });
    }
  } else if (option === 'always' && adjacent) {
    context.report({
      node: node,
      loc: {
        start: openingToken.loc.start,
        end: node.name.loc.start
      },
      message: ALWAYS_MESSAGE,
      fix: function(fixer) {
        return fixer.insertTextBefore(node.name, ' ');
      }
    });
  }
}

function validateBeforeClosing(context, node, option) {
  // Don't enforce this rule for self closing tags
  if (!node.selfClosing) {
    const sourceCode = context.getSourceCode();

    const NEVER_MESSAGE = 'A space is forbidden before closing bracket';
    const ALWAYS_MESSAGE = 'Whitespace is required before closing bracket';

    const lastTokens = sourceCode.getLastTokens(node, 2);
    const closingToken = lastTokens[1];
    const leftToken = lastTokens[0];

    if (leftToken.loc.start.line !== closingToken.loc.start.line) {
      return;
    }

    const adjacent = !sourceCode.isSpaceBetweenTokens(leftToken, closingToken);

    if (option === 'never' && !adjacent) {
      context.report({
        node: node,
        loc: {
          start: leftToken.loc.end,
          end: closingToken.loc.start
        },
        message: NEVER_MESSAGE,
        fix: function(fixer) {
          return fixer.removeRange([leftToken.range[1], closingToken.range[0]]);
        }
      });
    } else if (option === 'always' && adjacent) {
      context.report({
        node: node,
        loc: {
          start: leftToken.loc.end,
          end: closingToken.loc.start
        },
        message: ALWAYS_MESSAGE,
        fix: function(fixer) {
          return fixer.insertTextBefore(closingToken, ' ');
        }
      });
    }
  }
}

// ------------------------------------------------------------------------------
// Rule Definition
// ------------------------------------------------------------------------------

const optionDefaults = {
  closingSlash: 'never',
  beforeSelfClosing: 'always',
  afterOpening: 'never',
  beforeClosing: 'allow'
};

module.exports = {
  meta: {
    docs: {
      description: 'Validate whitespace in and around the JSX opening and closing brackets',
      category: 'Stylistic Issues',
      recommended: false,
      url: docsUrl('jsx-tag-spacing')
    },
    fixable: 'whitespace',
    schema: [
      {
        type: 'object',
        properties: {
          closingSlash: {
            enum: ['always', 'never', 'allow']
          },
          beforeSelfClosing: {
            enum: ['always', 'never', 'allow']
          },
          afterOpening: {
            enum: ['always', 'allow-multiline', 'never', 'allow']
          },
          beforeClosing: {
            enum: ['always', 'never', 'allow']
          }
        },
        default: optionDefaults,
        additionalProperties: false
      }
    ]
  },
  create: function (context) {
    const options = Object.assign({}, optionDefaults, context.options[0]);

    return {
      JSXOpeningElement: function (node) {
        if (options.closingSlash !== 'allow' && node.selfClosing) {
          validateClosingSlash(context, node, options.closingSlash);
        }
        if (options.afterOpening !== 'allow') {
          validateAfterOpening(context, node, options.afterOpening);
        }
        if (options.beforeSelfClosing !== 'allow' && node.selfClosing) {
          validateBeforeSelfClosing(context, node, options.beforeSelfClosing);
        }
        if (options.beforeClosing !== 'allow') {
          validateBeforeClosing(context, node, options.beforeClosing);
        }
      },
      JSXClosingElement: function (node) {
        if (options.afterOpening !== 'allow') {
          validateAfterOpening(context, node, options.afterOpening);
        }
        if (options.closingSlash !== 'allow') {
          validateClosingSlash(context, node, options.closingSlash);
        }
        if (options.beforeClosing !== 'allow') {
          validateBeforeClosing(context, node, options.beforeClosing);
        }
      }
    };
  }
};